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\f0\b\fs24 \cf0 Climate Scientists Fear \'91Day After Tomorrow\'92 Scenario
\b0 \
by Tony Dokoupil\
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\cf0 Sept. 10, 2015 \'96 In the 2004 disaster flick \'93Day After Tomorrow,\'94 abrupt man-made climate change knocks the planet into a state of utter chaos. At the time, the movie\'92s vision of the apocalypse wasn\'92t seen as realistic. But that\'92s begun to change. \'a0\'a0\
2 new studies deepen the fear that global warming could shut down the circulation of the oceans, much as the movie portrays, dropping vast stretches of Asia into drought and exposing the whole Northern Hemisphere to severe ice and snow.\
Unlike gradual climate change, where the planet warms steadily, this change would be sudden and sharp enough to roil civilization\'97happening in as little as 3 years and resulting in as much as an 18\'b0F drop in average temperatures.\
Jud Partin is the lead author of the stronger of the 2 studies, supported by the National Science Foundation and published in the journal
\i Nature Communication
\i0 . He\'92s also a geophysicist at the University of Texas, and an unabashedly close viewer of a certain summer blockbuster starring Dennis Quaid as hero-scientist Jack Hall. \'93In the movie, they defy the laws of physics,\'94 Partin told MSNBC, referring to hurricanes that form over land and other impossible weather.\'a0\'93But they got the climate science more or less right.\'94\
The climate science deals with the \'93Atlantic thermohaline circulation,\'94 an oceanic conveyor belt that carries heat from the tropics to the north, where it warms Western Europe and Eastern North America. It\'92s a fragile pattern, dependent on precise levels of salinity. Partin and others believe it could stop as Greenland\'92s ice sheets melt, flooding the ocean with fresh water.\
To glimpse our possible future, Partin and his colleagues gathered new geological data and re-examined the deep past. They looked at an earlier, all-natural melt-off that happened about 12,000 years. Known as the \'93Younger Dryas,\'94 the period was defined by a deep chill across the northern latitudes.\
Ice core studies cited by Partin show an 18\'b0F drop in average temperatures across Greenland. New York and London would be slightly warmer, he believes, but still frigid, with average temperature drops of at least 12\'b0F. That might seem small, but even minute changes in the average are a signal of extreme swings in actual conditions. \'a0\
The effects of this temperature change would be felt in a matter of years or decades, rather than a century or longer. That\'92s because this part of the climate system seems to work more like a switch than a dial. Once a certain threshold is reached, there\'92s a big, fast swing in the conditions over large parts of the planet. \'a0\'a0\
\'93It would definitely change everyday life in Europe and North America,\'94 Partin told MSNBC. \'93Daily life would be drastically affected in these areas, in ways I can\'92t imagine or begin to address.\'94\
Some climate change deniers might want to use Partin\'92s research \'96 which focuses on cooling rather than warming \'96 to claim that scientists can\'92t make up their minds about climate change or that it won\'92t be hot or dangerous. They\'92d be wrong to assume that.\'a0\
The script of \'93The Day After Tomorrow\'94 does a decent job driving a stake through the issue. \'93Yes, it is a paradox, but global warming can trigger a cooling trend,\'94 says Dennis Quaid, launching into some on-screen exposition as the scientist Jack Hall.\
\'93The Northern Hemisphere owes its climate to the North Atlantic Current,\'94 Dr. Hall explains. \'93Heat from the sun arrives at the equator and is carried north by the ocean. But global warming is melting the polar ice caps and disrupting this flow,\'94 he continues. \'93Eventually it will shut down. And when that occurs, there goes our warm climate.\'94\
Parts of the movie are gross exaggerations that Partin says we don\'92t have to worry about, like unrelated extreme weather events and speeding up the time frame for change. The cooling, for example, happens in a matter of days, instead of years or more likely decades. The freeze is also deeper, with North America covered in glaciers almost overnight.\
But in other ways, the movie arguably doesn\'92t go far enough. Shortly before the release of \'93The Day After Tomorrow,\'94 the Pentagon commissioned a $100,000 study of abrupt cooling scenarios, triggered by a similar stagnation of the oceans.\
The authors envisioned \'93a world of warring states\'94 and \'93a significant drop in the human carrying capacity of the Earth,\'94 a future so bleak it could haunt even Hollywood. Partin also finds that a break in the ocean\'92s circulatory system could drop much of Asia into a famine-inducing drought.\'a0\
It\'92s this effect on rainfall, in fact, that may be his most troubling finding. Unlike the drop in temperature, he says, this shift in rainfall would occur more slowly and linger far longer, even if the world swiftly addressed its emissions problem. This, he says, is the \'93double edged sword\'94 of changes in ocean circulation.\'a0\
But are we heading for this doom? \'93That\'92s the billion dollar question. Just how probable is this? Well, it\'92s definitely not zero,\'94 said Partin. \'93Right now we have pretty strong evidence that the Greenland ice is not only melting but accelerating.\'94\
Greenland is coated in nearly 700,000 square miles of ice. Scientists already know that this ice cover is thinning and that the planet\'92s thermostat is being pushed up by man-made carbon emissions. In 2007 alone, according to a recent study, Greenland lost \'93the equivalent of 2 times all the ice in the Alps.\'94\'a0\
In another new study, published in the journal
\i Geophysical Research Letters
\i0 , 3 scientists from Germany\'92s Alfred Wegener Institute looked at the effect of this melting. Not only did they find evidence of an effect, they concluded that existing models may have underestimated the sensitivity of the ocean\'92s system.\
Even a relatively small change in the ocean\'92s salinity, the researchers write, \'93corresponds to a significant temperature decrease, of up to 40%\'94 across North America and Europe.\'a0\
That doesn\'92t surprise Joshua Willis, an oceanographer at NASA\'92s Jet Propulsion Laboratory, who was not involved in the latest studies. \'93In a lot of areas of climate change, we\'92re seeing that earlier estimates were conservative,\'94 he told MSNBC.\
He\'92s the lead investigator of a 5-year, $30 million study that should help scientists determine Greenland\'92s melt-rate with unprecedented accuracy. The official NASA \'93mission\'94 is known as Oceans Melting Greenland\'97yes, it\'92s called operation OMG.\
But Willis isn\'92t ready to panic, let alone call Dennis Quaid.\'a0\'93It\'92s not going to be the \'91Day after Tomorrow,\'92\'94 he said. \'93Impacts like that are way overstated.\'94\
Still, both he and Partin share a hope that the world leaders will rein in greenhouse gas emissions, and soon. \'93The longer we wait,\'94 said Partin, \'93the longer it will take for us to get back to normal.\'94\
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\cf0 www.msnbc.com/msnbc/climate-scientists-fear-day-after-tomorrow-scenario}